Guys! Any airfoil moving with an angle of attack to the freestream generates lift. Sometimes the lift ain't upward but is forward and is called thrust but it is lift all the same. Take the case of a yacht sailing into wind. You tack, the angle of attack takes effect, the sail bellies out into the wind, the yacht moves forward. Now run out the jib sail. In the narrow gap twixt (slat??) jib and main the air speeds up faster, creating more lift. Even a brick if thrown hard enough flies. Sixteen-ton bricks flew at Binbrook until the 1980s. But you don't need to believe silly old me. Read the texts, go to a wind tunnel, talk to the experts. And to take a leaf out of someone elses book if they don't lift they drag, all things drag, if they don't lift as well (in this case lift means thrust) they don't work.